void test_resistors(void);
void test_DC(void);
void test_freq(void);
void test_led(void);
void test_vcos(void);
void test_pll1(void);
void test_pll2(uint8_t which);
void test_pll3(void);
void test_uart(void);
uint16_t find_freq_for_dc(uint8_t which, uint16_t val);
uint16_t  test_bw(uint8_t which, uint16_t center);
